Embolic protection is utilized throughout the vasculature to prevent the potentially fatal passage of embolic material in the bloodstream to smaller vessels where it can obstruct blood flow. The dislodgement of embolic material is often associated with procedures which open blood vessels to restore natural blood flow such as stenting, angioplasty, arthrectomy, endarterectomy or thrombectomy. Used as an adjunct to these procedures, embolic protection devices trap debris and provide a means for removal for the body.
One widely used embolic protection application is the placement of filtration means in the vena cava. Vena cava filters (VCF) prevent the passage of thrombus from the deep veins of the legs into the blood stream and ultimately to the lungs. This condition is known as deep vein thrombosis (DVT), which can cause a potentially fatal condition known as pulmonary embolism (PE).
The next advancement in filters added the element of recoverability. Retrievable filters were designed to allow removal from the patient subsequent to initial placement. These filters can incorporate retrieval features that can be grasped and/or secured by a retrieval device, such as a snare based retrieval device. Grasping the retrieval feature using a snare generally requires the user to manipulate the snare over the retrieval feature, which can be difficult due to a variety of factors, such as retrieval feature geometry and location within the lumen, the structure and properties of the snare, and ability to visualize the retrieval feature and/or snare using a real-time visualization technique such as fluoroscopy.
Accordingly, it would be desirable to have an improved retrieval device that would facilitate engagement with a retrieval feature on a device making retrieval and/or manipulation of the device easier and faster to complete.